The present invention relates to a method of extracting outline loops of a binary image stored in the raster scanning order, and an apparatus therefor.
Conventionally, an apparatus for extracting an outline loop from a binary dot pattern extracts an outline loop of a character pattern of a binary image, and stores the extracted outline loop in the form of vector information. Extraction of an outline loop of a binary image begins with finding out of a trace start point for tracing an outline loop of a target binary image. When the trace start point is found, the outline loop of the image is traced in turn from the trace start point. A trace end mark is assigned to traced dots on the outline loop. When the entire outline loop is traced, the marked dot string corresponds to the outline loop to be obtained. Such a procedure is repetitively executed to extract all outline loops in a target image.